High-pressure phase relations in Zn2SiO4 system: A first-principles study

In order to clarify phase relation of Zn2SiO4 system, first-principles DFT calculations of 11 phases were conducted. We confirmed that phases III and IV are retrograde phases. Instead, Na2CrO4- and Ag2CrO4-structured phases are most likely candidate structures for high-pressure phases of III and IV, respectively. A transition of phase II to spinel found during optimization was discussed in relation to similar transition known for nitrides.